In recent years, “tailor made medicine” is gaining recognition, which takes into consideration individual differences between patients, and a search for a marker to distinguish a cancer against which a pharmaceutical agent is effective from a cancer against which the pharmaceutical agent is ineffective is considered to be necessary. It is an attempt to ethically and medically improve cost performance of medication treatment by administering a pharmaceutical agent to patients after verification in advance of the probability of effect thereof, thereby to enhance efficacy as well as avoid toxicity of the pharmaceutical agent, and to reduce insignificant use of the pharmaceutical agent. In cancer treatment, the development of a method for predicting the efficacy of anticancer agents has been desired, because it can be an important means to bridge the gap between basic study and clinical application.